AdeV

Right... I;ve done the wire thing, and I'm getting code 13 (RPM Signal No. 2). I don't have a repair manual, so if anyone does who's willing to look up what that means & what the next steps/fixes are, I'd be properly grateful, thanks in advance!

Hi Ruud, Looks like you might be right :( Yesterday I had to drive 200 miles to Scotland. About half way up, I noticed the occasional bump (at around 2900-3000rpm). The engine light was on all the way; however - as before - the long run seemed to cure the rough idle. Today, on the return trip, no engine light or idle roughness, but after about 5-6 miles, the engine began to hiccough both severely and at higher rpms. As I was still nearly 200 miles from home & have no breakdown policy (this IS a Lexus after all....) I persevered. Accelerating was a very dodgy affair with the engine coughing and lurching very badly, but once up to speed she wasn't so bad. Worse on the hills, i.e. this problem definitely manifests under load. 200 miles and some kangarooing later (worse at the end of the trip) I have arrived home - even when badly sick, it seems nothing will stop the LS400... Interestingly, the EML light is no longer lit, and the idle roughness appears to have completely gone; but the high-speed lurching and outrageously bad acceleration mean the car is basically on sick leave now until fixed or replaced. I'm going to try the coils & ECU as a first stop; plugs & wires I'm happy should be OK. My biggest concern is that I've knocked years of life out of the gearbox, some of the lurches produced some noticable bangs from the back axle...

Thanks for the replies chaps... The lumpy running started before the weather went cold; the cold may be exacerbating it, but it's not the cause. Also, the rapidity with which it came on (i.e. it's never happened before, and suddenly it's full-on) would tend, I think, to rule out dirty throttle bodies, etc. I changed the plugs less than a year & less than 20k miles ago. I couldn't rule out the coils as I've not changed those in my ownership. My car is the Mk2, is that still compatible with the OBD2 cable? There's a diagnostics plug atop the engine, but I know nothing about car ECU systems...

A few days ago, I stuck 20 quid of fuel in the tank, and shortly afterwards (maybe 10 miles?) I started experiencing lumpy idling, cutting out at lights, and the EML coming on & off. Assuming it was just some water in the fuel, I went for a run up & down the motorway, which seemed to cure it. I ran it until maybe 10 miles after the fuel light came on & put 20 quid more in from my usual garage (not the suspect one). However, the lumpiness has returned, even more so if anything, and now the EML comes on even if the lumpiness doesn't appear to be present. Power output seems unaffected, the engine still revs freely, and under hard power ( ) all seems well - same at motorway speeds. However, she's become a nightmare to drive around town. Any suggestions as to a fix? Do I just need to ride it out, run the tank as empty as I dare, then fill up to the brim with good fuel? Or some other strategy? Also, the EML thing, am I right in thinking that's now an MOT failure? If so, I need to get it turned off. I'm competent around computers, and with the correct cable & software could get the fault codes & reset the light - but what s/w & what cable, is eBay my friend here or does someone have a recommendation? Cheers! Ade.

You don't actually need an intercooler with either a turbo OR a supercharger. Science bit -> They are desirable on both because the reduction in temperature (compressing a gas causes it to get hot) results in a higher charge density. The higher the density of the air entering the system (i.e. the cooler it is), the more air you get, the more fuel you can add, and the more power output. If the air is still red hot, you simply can't fit as much in (even though the pressure might be the same or even higher), and you get less of a boost. Adding an intercooler would add a few HP to his claim of 400 (or 397 actually), enough to be significant I suspect, as most performance critical turbo or supercharger applications use an intercooler. In English -> It goes faster B)

I've also watched it once, and some bits of it occasionally, and only because they were "over here" looking at a Morgan. The piece itself wasn't that bad, sort of a cross between Old Top Gear and watching paint dry (which I am doing today). As far as I can tell, they are simply re-creating each individual episode of original TG? e.g. the boat/plane/car race (boat/train/car in the UK, but they don't have trains over there...); the "buy an old car and take it to the proving ground put eggs in a colander above the presenters head" trick. It's like an old VHS copy of a copy of a copy: You can watch it, but all the time you're wishing you had the original.

Bump... Has no-one got any thoughts? Should I repost in the Engine subforum perhaps?

The easiest way Dave, if you remember to do it... is to brim the car full (or fill to the first click - this works accurately only if you use the same pump next time); drive your test journey, then fill up again. Note the mileage, convert litres to gallons, divide t'one by t'other, and you've got your MPG figure for that journey. IIRC, the Mk4 has a fuel computer, so you can just read the MPG off the dash? I'm slightly surprised none of the earlier Lexii had computers (e.g. trip time, fuel usage, stopwatch, yada yada) - my early '80s Ford had one...

Was she concieved there? [cue confused Americans...] No mate. The M6 is a very popular motorway. Everyone around here has been on the M6!!! That had also occurred to me.... but I thought I'd throw in an obscure Douglas Adams reference.... (for those who know, the girl called Fenchurch in book 4 of Hitch Hiker's Guide to the Galaxy - so called because she was conceived in the ticket queue at Fenchurch Street Station in London)

Was she concieved there? [cue confused Americans...]

Motorworld sell Carplan paint, if there's one near you. Ade, there is nothing near me but sheep and seagulls mate.. Ill google motorworld tomorrow. Cheers mate. Silver paint and sheep.....now that gives me an idea!! "something for the weekend sir?" LOL! Just drive East until you stumble across the M6, then head South until you reach civilisation - job done!

Motorworld sell Carplan paint, if there's one near you.

All through summer (indeed, any time the outside temperature is above about 12 degrees), my Mk2 LS400's temperature behaves perfectly - straight to 1/2 way & stays there, solid as a rock. As soon as the outside temperature dips below 10-12, the temperature gauge stops coming up to half way & hovers anywhere between the 1st mark (if it's really cold) & just under 1/2 way. I've never noticed it affect the cabin temperature. I don't believe it's a t-stat fault, as the car warms up (starts blowing hot air) after about the same time no matter what the outside temperature. Yesterday, I noticed a slight dip in the cabin air temperature at one point, which is a new symptom, but that may just be a low water level (my top hose occasionally leaks). The car did the same thing for the last 2 winters, but not the 1st winter I owned it. Any ideas?

It's actually to warm the vaporiser, not cool it (without heat, they frost up in no time & stop working). Thanks Ade, learning all the time! Any thoughts on what I can do to stop the draw to the vaporiser and away from the heater matrix at low revs??? Will contact the lpg installer tomorrow and see if he has any suggestions. Unfortunately, I can't think of anything simple; it sounds like you need a restrictor valve to divert more water through the heater matrix than through the vaporiser - if it's too restrictive though, you might end up with your gas valve freezing & the engine stalling (or, best case scenario, switching back to petrol).

It's actually to warm the vaporiser, not cool it (without heat, they frost up in no time & stop working).

It's worth watching eBay for the centre discs - I managed to get a set of 4 brand new ones for about a fiver + a few quid delivery. I haven't fitted them to the car yet because the wheels look so bad, having perfect centres would just accentuate the badness... Anyway, I've bought a can of carplan primer & silver-25 paint, so I'm going to have a crack at the spare this weekend (ironically, the spare is the best looking of the lot!). If it works out well, then I'll do the others. Question - can I bake them with a gas-fired space heater, or do I need to use dry heat, e.g. an electric unit? Can the wheel be baked with a tyre on it, or does it need to come off first? (if so, I'll forego the baking this time).

Don't know about %, but I've almost got a full house now: Flickery speedo/revcounter needles, blacked out LCDs, PAS leak (and not from the O-ring as I've changed that AND put a load of instant gasket around the area). Just need the radio light to fail now I guess... Still, all things considered, that's not bad for a +200K motor. A member on here can fix your dash, there is an overhaul kit available for the p/s pump a couple of hundred quid should fix it...a friend of mine just paid £132 to have a bulb replaced on his Merc. ! Get it fixed you know you want to.. Oooh, where can I get the PAS pump refurb kit? Maurice hasn't had any pumps available for ages, and mine is really starting to leak big style. I'm aware of the dash fixes, but until all the lights fail (or flicker), I'm willing to put up with it. Same with the LCD, it's been blacked out since I bought the car, the only annoyance is trying to see the time in the dark. Interestingly, after about 2 hours driving, the LCD usually starts working after a fashion - enough to read at any rate. The thing is, this is a 200,000+ mile car now, it's got a few dents & scratches, the PAS pump is noisy & leaky... the starter motor doesn't turn off when you release the key when its cold (longest overrun time - 5s, luckily, the solenoid is disengaging the gear just fine, it's the motor that doesn't stop), fixing all the issues is going to take time & money. Having just done the timing belt & water pump, I'm kind of committed to keeping it - the only reason I might not is if I upgrade to a Mk4, but while mine remains reliable, I don't see the point. And it's still a hoot to hoof it off a roundabout in the wet for some sideways V8 action :)

There's 1 "idler" pulley, and 1 tensioner, which is like a pulley but on a bracket. If both are present, you've got everything you need (well, assuming there's a belt in there too...) If there's only one pulley (on a bracket), that's the tensioner. You'll need to purchase an idler too, ideally. Japarts do them as separate items, or have a look on eBay. When I did mine, I got a pump/pulley/tensioner/belt kit from a US seller - it was significantly cheaper than the UK equivalent even with the postage; and the chap helpfully put a low $ value on the customs sticker so no VAT or duty either, bonus! PM me if you want the US seller's details. Cheers, Ade. EDIT: Oops. I didnt read page 2...

Don't know about %, but I've almost got a full house now: Flickery speedo/revcounter needles, blacked out LCDs, PAS leak (and not from the O-ring as I've changed that AND put a load of instant gasket around the area). Just need the radio light to fail now I guess... Still, all things considered, that's not bad for a +200K motor.

+1 .... I need to get some antifreeze in mine, still haven't changed the water after doing the water pump/cambelt.... (oops)

The paint is CarPlan and the colour on the lid is Silver-25 Phil Cool, ta for that. My wheels are also dead scabby. I've been considering sending them to that crowd in Blackpool who do full refurbs, but if I can tart them back up with a bit of paint, that'll do for now :)

It might be rust/crap in the end of the cable; had this problem with Dad's Mk3, he took the whole lot to bits & liberally WD40'd the area, and after a good lot of wiggling & fiddling, freed it all up. In his case, you could feel in the pedal that there wasn't much of anything going on, a fact that was very noticable once normal operation was restored.

Most autos will start in "P" or "N"; it's if it'll start in a gear you've got issues. I can't specifically remember if I've ever started the Lexus in "N".

You didn't call your car Christine by any chance, did you? Pretty much the only things I can think of, which you may already have eliminated, are either a vacuum leak somewhere, or an air leak after the MAF sensor. Other than that, I reckon you'll just have to say it's haunted by the ghost of Ralph Nader (or maybe Ralph Nader's dad, as the man himself is still with us).

Hmm, some of those lists are seriously long (and seriously good...) Mine shows a disturbed mind I think: '83 Ford Granada 2.8i GL Estate (at 18 years old....!) - went banger racing in '95. '8X Ford Escort 1.9 Diesel (company car, PoS) '84 Ford Granada 2.8i Ghia X - scrapped sometime around '99-2000. '84 Ford Granada 2.8i Ghia X Executive - scrapped sometime around '99-2000. '91 Rover 820 Turbo (not a Vitesse - fabulously quick, mega expensive on oil, ultimately very fragile) - scrapped sometime around '99-2000. '89 Vauxhall Senator 3.0i 12v '99 Audi A4 2.4SE (lease car - never again) - returned 2002 at end of lease Back to the Senator after the Audi, then '99 Jaguar S-type 3.0 SE (very expensive, very fragile, nightmare. Nice when it worked.) - sold 2005 Back to the Senator again '84 Ford Granda 2.8i Ghia X (there's a pattern emerging here....) Back to the Senator '94 LS400 Sold the Senator in 2009, it was scrapped within a year, sadly. That was one comfy car. Sold the Granada & bought another one with the proceeds, a 2.8i Ghia X Estate Bought another LS400 as an engine donor car (for the 4.0 Granny project) I still have an "H" reg Pug 205 1.9 auto, bought from my late Grandmother for my sister when she was at University... Current cars include a Ford Capri race car and a Capri bare shell. Oh, also a Bedford VAM coach (33ft...) and a Ford Cargo 7.5t breakdown wagon.